Adding some logic to handle unpivoting boolean columns (#305)

Readme & deleted the 'remove' line which does nothing.

Finish off upivot boolean logic

Update changelog [ci skip]

CHANGELOG.md

@@ -1,10 +1,10 @@
 # dbt-utils v0.6.5 (unreleased)
 ## Features
 * Add new `accepted_range` test ([#276](https://github.com/fishtown-analytics/dbt-utils/pull/276) [@joellabes](https://github.com/joellabes))
-* Make `expression_is_true` work as a column test (code originally in [#226](https://github.com/fishtown-analytics/dbt-utils/pull/226/) from [@elliottohara](https://github.com/elliottohara), merged via [#313]) 
+* Make `expression_is_true` work as a column test (code originally in [#226](https://github.com/fishtown-analytics/dbt-utils/pull/226/) from [@elliottohara](https://github.com/elliottohara), merged via [#313])
 
 ## Fixes
-
+* Handle booleans gracefully in the unpivot macro ([#305](https://github.com/fishtown-analytics/dbt-utils/pull/305) [@avishalom](https://github.com/avishalom))
 ## Under the hood
 
 # dbt-utils v0.6.4
@@ -24,7 +24,6 @@
 
 - Bump `require-dbt-version` to `[">=0.18.0", "<0.20.0"]` to support dbt v0.19.0 ([#308](https://github.com/fishtown-analytics/dbt-utils/pull/308), [#309](https://github.com/fishtown-analytics/dbt-utils/pull/309))
 
-## Fixes
 
 # dbt-utils v0.6.2
 

README.md

@@ -707,6 +707,7 @@ Arguments:
 
 #### unpivot ([source](macros/sql/unpivot.sql))
 This macro "un-pivots" a table from wide format to long format. Functionality is similar to pandas [melt](http://pandas.pydata.org/pandas-docs/stable/generated/pandas.melt.html) function.
+Boolean values are replaced with the strings 'true'|'false'
 
 Usage:
 ```

integration_tests/data/cross_db/data_cast_bool_to_text

@@ -0,0 +1,4 @@
+id,my_bool
+1,true
+2,false
+3,

integration_tests/data/sql/data_unpivot_bool.csv

@@ -0,0 +1,4 @@
+customer_id,created_at,status,segment,is_updated
+123,2017-01-01,active,tier 1,TRUE
+234,2017-02-01,active,tier 3,FALSE
+567,2017-03-01,churned,tier 2,

integration_tests/data/sql/data_unpivot_bool_expected.csv

@@ -0,0 +1,10 @@
+customer_id,created_at,prop,val
+123,2017-01-01,segment,tier 1
+123,2017-01-01,status,active
+123,2017-01-01,is_updated,true
+234,2017-02-01,segment,tier 3
+234,2017-02-01,status,active
+234,2017-02-01,is_updated,false
+567,2017-03-01,status,churned
+567,2017-03-01,is_updated,
+567,2017-03-01,segment,tier 2

integration_tests/models/sql/schema.yml

@@ -96,6 +96,11 @@ models:
       - dbt_utils.equality:
           compare_model: ref('data_unpivot_expected')
 
+  - name: test_unpivot_bool
+    tests:
+      - dbt_utils.equality:
+          compare_model: ref('data_unpivot_bool_expected')
+
   - name: test_star
     tests:
       - dbt_utils.equality:

integration_tests/models/sql/test_unpivot_bool.sql

@@ -0,0 +1,32 @@
+
+-- snowflake messes with these tests pretty badly since the
+-- output of the macro considers the casing of the source
+-- table columns. Using some hacks here to get this to work,
+-- but we should consider lowercasing the unpivot macro output
+-- at some point in the future for consistency
+
+{% if target.name == 'snowflake' %}
+    {% set exclude = ['CUSTOMER_ID', 'CREATED_AT'] %}
+{% else %}
+    {% set exclude = ['customer_id', 'created_at'] %}
+{% endif %}
+
+
+select
+    customer_id,
+    created_at,
+    case
+        when '{{ target.name }}' = 'snowflake' then lower(prop)
+        else prop
+    end as prop,
+    val
+
+from (
+    {{ dbt_utils.unpivot(
+        relation=ref('data_unpivot_bool'),
+        cast_to=dbt_utils.type_string(),
+        exclude=exclude,
+        field_name='prop',
+        value_name='val'
+    ) }}
+) as sbq

macros/cross_db_utils/cast_bool_to_text.sql

@@ -0,0 +1,15 @@
+{% macro cast_bool_to_text(field) %}
+  {{ adapter.dispatch('cast_bool_to_text', packages = dbt_utils._get_utils_namespaces()) (field) }}
+{% endmacro %}
+
+
+{% macro default__cast_bool_to_text(field) %}
+    cast({{ field }} as text)
+{% endmacro %}
+
+{% macro redshift__cast_bool_to_text(field) %}
+    case
+        when {{ field }} is true then 'true'
+        when {{ field }} is false then 'false'
+    end::text
+{% endmacro %}

macros/sql/unpivot.sql

@@ -62,7 +62,12 @@ Arguments:
       {%- endfor %}
 
       cast('{{ col.column }}' as {{ dbt_utils.type_string() }}) as {{ field_name }},
-      cast({{ col.column }} as {{ cast_to }}) as {{ value_name }}
+      cast(  {% if col.data_type == 'boolean' %}
+           {{ dbt_utils.cast_bool_to_text(col.column) }}
+             {% else %}
+           {{ col.column }}
+             {% endif %}
+           as {{ cast_to }}) as {{ value_name }}
 
     from {{ relation }}